United States
One of the two national GSM carriers, T-Mobile,[42] will unlock handsets for those with active account in good standing for at least 40 days and no unlock code request in the last 90 days. T-Mobile will also unlock a phone if the full retail price is paid and proof of purchase is provided through a faxed document. The other, AT&T Wireless,[43] will usually do so once one has concluded his or her contract, but may also unlock the phone in some other situations as well. Neither carrier is compelled to unlock phones by any law or regulation, and they may choose not to unlock certain phones. For example, AT&T has stated that they themselves will not unlock iPhones under any circumstances, regardless of the legality of doing so, even after customers are out of contract.[44]
It was first publicly discussed by the FCC in 2006, after a submission to the US Librarian of Congress concerned respect to Digital Millennium Copyright Act (DMCA) exemptions, and Stanford law professor Jennifer Granick specifically stated that the Federal Communications Commission (FCC) does not prohibit handset locking.[45] The DMCA formerly was claimed to criminalize unlocking. However, an exemption introduced on November 27, 2006 specifically permits it. The exemption was scheduled to expire on October 27, 2009,[46] but was extended on an interim basis, because the Register of Copyrights had not yet completed its triennial review of DMCA exemptions.[47] In July 2010, the Librarian of Congress extended the DMCA exemption for another 3 years.[48][49]